import type { DamageSchool } from "./itemStats";
import { wow335HunterPetBaseDefenseForLevel } from "./wow335HunterPetDefenseData";

export { wow335HunterPetBaseDefenseForLevel } from "./wow335HunterPetDefenseData";
export type { Wow335HunterPetBaseDefense } from "./wow335HunterPetDefenseData";

export type Wow335HunterPetMagicSchool = Exclude<DamageSchool, "physical">;

export type Wow335HunterPetOwnerResistances = Readonly<Record<Wow335HunterPetMagicSchool, number>>;

export interface Wow335HunterPetInheritedDefenses {
  /** Owner-derived contribution only; pet base armor and pet modifiers are separate. */
  readonly armor: number;
  /** Owner-derived contribution for the six non-physical schools. */
  readonly resistances: Wow335HunterPetOwnerResistances;
}

export const WOW335_HUNTER_PET_OWNER_ARMOR_INHERITANCE_PERCENT = 35;
export const WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT = 40;

function finite(value: number): number {
  return Number.isFinite(value) ? value : 0;
}

function float32(value: number): number {
  const rounded = Math.fround(finite(value));
  return Number.isFinite(rounded) ? rounded : 0;
}

/** Match TrinityCore CalculatePct<T>: float arithmetic, then conversion to T. */
function calculatePctAsInteger(base: number, percent: number): number {
  const product = float32(float32(base) * float32(percent));
  const result = float32(product / float32(100));
  return Math.trunc(result);
}

/**
 * Compute only the owner-derived defense contribution for a Hunter pet.
 * Callers still need to combine the pet's own armor/aura values and use these
 * values as the pet's owner-dependent defenses change.
 */
export function wow335HunterPetInheritedDefenses(
  ownerArmor: number,
  ownerResistances: Wow335HunterPetOwnerResistances,
): Wow335HunterPetInheritedDefenses {
  const inherit = (value: number, percent: number): number => calculatePctAsInteger(value, percent);

  return {
    armor: inherit(ownerArmor, WOW335_HUNTER_PET_OWNER_ARMOR_INHERITANCE_PERCENT),
    resistances: {
      holy: inherit(ownerResistances.holy, WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT),
      fire: inherit(ownerResistances.fire, WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT),
      nature: inherit(ownerResistances.nature, WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT),
      frost: inherit(ownerResistances.frost, WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT),
      shadow: inherit(ownerResistances.shadow, WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT),
      arcane: inherit(ownerResistances.arcane, WOW335_HUNTER_PET_OWNER_MAGIC_RESISTANCE_INHERITANCE_PERCENT),
    },
  };
}

export interface Wow335HunterPetArmorInputs {
  /** `pet_levelstats.armor`, or the pet's current BASE_VALUE if modified. */
  readonly petBaseArmor: number;
  /** Effective pet Agility after pet-owned stat modifiers. */
  readonly petAgility: number;
  /** Current effective owner armor. */
  readonly ownerArmor: number;
  /** TrinityCore BASE_PCT multiplier; defaults to 1. */
  readonly baseArmorMultiplier?: number;
  /** Flat pet armor from TOTAL_VALUE; defaults to 0. */
  readonly petFlatArmor?: number;
  /** TrinityCore TOTAL_PCT multiplier; defaults to 1. */
  readonly totalArmorMultiplier?: number;
}

/**
 * Compose pet armor using the pinned TrinityCore 3.3.5 Guardian::UpdateArmor
 * order, including integer CalculatePct<T> owner inheritance and final
 * int32(value) truncation. This does not calculate incoming-damage mitigation.
 */
export function wow335HunterPetArmorForProfile(inputs: Wow335HunterPetArmorInputs): number {
  const baseArmorMultiplier = float32(inputs.baseArmorMultiplier ?? 1);
  const petFlatArmor = float32(inputs.petFlatArmor ?? 0);
  const totalArmorMultiplier = float32(inputs.totalArmorMultiplier ?? 1);
  const inheritedArmor = calculatePctAsInteger(
    inputs.ownerArmor,
    WOW335_HUNTER_PET_OWNER_ARMOR_INHERITANCE_PERCENT,
  );

  let value = float32(float32(inputs.petBaseArmor) * baseArmorMultiplier);
  value = float32(value + float32(float32(inputs.petAgility) * float32(2)));
  value = float32(value + float32(petFlatArmor + float32(inheritedArmor)));
  value = float32(value * totalArmorMultiplier);

  return Math.trunc(value);
}

/** Compose the pinned entry-1 baseline with current owner armor. */
export function wow335HunterPetArmorForLevel(
  level: number,
  ownerArmor: number,
  modifiers: Omit<Wow335HunterPetArmorInputs, "petBaseArmor" | "petAgility" | "ownerArmor"> = {},
): number {
  const baseline = wow335HunterPetBaseDefenseForLevel(level);
  return wow335HunterPetArmorForProfile({
    ...modifiers,
    petBaseArmor: baseline.armor,
    petAgility: baseline.agility,
    ownerArmor,
  });
}